std::stoul, std::stoull

< cpp‎ | string‎ | basic string
Defined in header <string>
unsigned long      stoul( const std::string& str, size_t *pos = 0, int base = 10 );
(1) (since C++11)
unsigned long long stoull( const std::string& str, size_t *pos = 0, int base = 10 );
(2) (since C++11)

Interprets an unsigned integer value in the string str.

1) calls std::strtoul(str.c_str(), pos, base)
2) calls std::strtoull(str.c_str(), pos, base)

Function discards any whitespace characters (as identified by calling isspace()) until first non-whitespace character is found. Then it takes as many characters as possible to form a valid base-n (where n=base) unsigned integer number representation and converts them to an integer value. The valid unsigned integer value consists of the following parts:

  • (optional) prefix (0) indicating octal base (applies only when the base is 8 or 0)
  • (optional) prefix (0x or 0X) indicating hexadecimal base (applies only when the base is 16 or 0)
  • a sequence of digits

The set of valid digits for base-2 integer is 01, for base-3 integer is 012, and so on. For bases larger than 10, valid digits include alphabetic characters, starting from Aa for base-11 integer, to Zz for base-36 integer. The case of the characters is ignored. In non-default locales, additional numeric formats may be accepted.

If the value of base is 0, the numeric base is auto-detected: if the prefix is 0, the base is octal, if the prefix is 0x or 0X, the base is hexadecimal, otherwise the base is decimal.

The index of the first unconverted character is stored in pos. If NULL is passed as pos, it is ignored.


[edit] Parameters

str - the string to convert
pos - address of an integer to store the index of the first unconverted character
base - the number base

[edit] Return value

The string converted to the specified unsigned integer type.

[edit] Exceptions

  • std::invalid_argument if no conversion could be performed
  • std::out_of_range if the converted value would fall out of the range of the result type or if the underlying function (std::strtoul or std::strtoull) sets errno to ERANGE.

[edit] See also

converts a string to a signed integer
(function) [edit]
converts a string to a floating point value
(function) [edit]